I love this picture! Is it a technical canyon, or is it a place you could go with small kids who know nothing about technical climbing/canyoneering?
It all depends - I would only take them if it was good weather and then just do a portion of the hike. The slot is one of the longest in the world and the hike out is in deep sand and there is an iffy spot where most need a rope to get by. But! You could take them as far as they want to hike and then go back the same way. There are no significant elevation changes either so it's kid friendly that way. The good part about that is you can just sign for a permit right at the trailhead as long as you are only day hiking. There are some nice pictographs at the start of the hike in Wire Pass. Willis Creek - the first photo in my album is very kid friendly.